how transformer are used for long distance transmission of power? Justify which type of transformer core will you prefer
Answers
Answer:
Transformers can be used either to increase the voltage (called "stepping up") or decrease the voltage ("step down"). ... First, the voltage of electricity coming from the power plant is "stepped up" using transformers to the right level for long-distance transmission
High voltage transformers mean that the kVA rating would also be more, in most cases.
More voltage requires thicker insulation and hence the winding becomes bulky.
In core type design, both of the LV and HV windings are distributed in two limbs, which becomes necessary at times to accomodate the larger windings, otherwise the shell type design would be more in height to accomodate the same winding.
Also higher the voltage, higher would be the heat loss, which is very crucial to dissipate or the machine would fail. Core type construction has exposed windings, which means better cooling.
Also due to easily accessible windings, the tapping and repairing is easier in core type.
Insulation breakdown is the most feared cause of failure of an HV transformer, and prolonged heating causes insulation degradation at a speedy pace, so universally core type design is accepted